a slab of reinforced concrete providing a footing on yielding soil, usually for a whole building, so that the weight of the soil that would be displaced by the settlement of the building exceeds the weight of the building itself; mat.

verb (used with object)

5.

to transport on a raft.

6.

to form (logs or the like) into a raft.

7.

to travel or cross by raft.

8.

(of an ice floe) to transport (embedded organic or rock debris) from the shore out to sea.